Effect of 4‐Amino‐3,5,6‐trichloropicolinic acid on Protein Synthesis

The effects of 4‐amino‐3,5,6‐trichloropicolinic acid (picloram) on protein synthesis in bean ( Phaseolus vulgaris L. cv. ‘Astro’) hypocotyl and hook tissues were studied. Picloram (10 ‐4 M ) was shown to have a stimulatory effect on 14 C‐1‐DL‐leucine uptake in hook but not hypocotyl tissues. Maximum leucine incorporation and maximum total protein concentration occurred in hook tissues treated with 10 ‐4 M picloram. Inhibition of protein synthesis with cycloheximide (CH) and erythromycin (ERY) indicates that endogenous and picloram‐stimulated protein synthesis is a function of the 80S cytoplasmic ribosomes rather than 70S chloroplast or mitochondria ribosomes.